JPS5824246A - Automatic equalization system for attenuation distortion - Google Patents

Automatic equalization system for attenuation distortion

Info

Publication number
JPS5824246A
JPS5824246A JP56123272A JP12327281A JPS5824246A JP S5824246 A JPS5824246 A JP S5824246A JP 56123272 A JP56123272 A JP 56123272A JP 12327281 A JP12327281 A JP 12327281A JP S5824246 A JPS5824246 A JP S5824246A
Authority
JP
Japan
Prior art keywords
circuit
frequency
signal
component
attenuation distortion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP56123272A
Other languages
Japanese (ja)
Inventor
Susumu Sekiguchi
進 関口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP56123272A priority Critical patent/JPS5824246A/en
Publication of JPS5824246A publication Critical patent/JPS5824246A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising
    • H04B3/10—Control of transmission; Equalising by pilot signal
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C7/00—Parts, details, or accessories of chairs or stools
    • A47C7/36—Support for the head or the back
    • A47C7/40—Support for the head or the back for the back
    • A47C7/44—Support for the head or the back for the back with elastically-mounted back-rest or backrest-seat unit in the base frame
    • A47C7/443—Support for the head or the back for the back with elastically-mounted back-rest or backrest-seat unit in the base frame with coil springs

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

PURPOSE:To automatically equalize the attenuation distortion of a line by simultaneously transmitting two signals; a nearly center frequency and an upper limit frequency of the transmission band of a cable transmitting circuit, and detecting the level difference in arrival between those two signals at a reception side. CONSTITUTION:A signal of a nearly center frequency f0 of a transmission band is outputted from an oscillating circuit 1 and divided into two by a distributing circuit 2; one is converted at a part 3 into a rectangular wave, which is multiplied at a part 4 to obtain a frequency f2= 2f0. The signal is converted at a part 5 into a sine wave, which is mixed with a signal of the frequency f0 at a part 6, whose output is sent to a cable transmitting circuit 7. The signal transmitted by the circuit 7 is passed through a receiving teminal IN and a switch 17 and branched by a distributing circuit 8; one component is passed through a BPF9 to select the frequency f0, and the selected frequency signal is processed by full-wave rectification 10 to obtain a DC component. The other component is passed through a BPF11 to select the frequency f2, and the selected frequency signal is processed by full-wave rectification 12 to obtain a DC component, which is compared with said component of frequency f0 by a comparing circuit 13. Thus, the circuit 13 detects their voltage difference, which is converted at a part 14 into a digital binary signal to be sent to a logical circuit 15. According to the voltage difference, the circuit 15 changes the numbers of steps of an equalizing circuit 16 to perform automatic equalization.

Description

【発明の詳細な説明】 本発明はケーブル伝送回線の減衰歪を自動的に等化する
方式に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically equalizing attenuation distortion of a cable transmission line.

市外ケーブル又は、各種同軸ケーブルを用いた伝送回線
はケーブルの周波数特性がそのまま伝送帯域の減衰歪と
なって回線品質を劣化させる為（等什器を挿入し補正す
る必要がある。ケーブルの周波数特性は第１図の曲！Ｉ
２０に示すように、周波数が高くなれば損失が増加する
。その損失はケーブルの静電容量、インダクタンス容量
が支配的で周波数に対しては対数で変化し、距離、温度
に正比例する。従って伝送有効帯域の中心周波数ｆｚ−
ｆｓに対しｆ２とのレベル差（Ｄ２）が求めることが出
来れば、前記中心周波数とｆｘのレベル差（Ｄｌ）は比
率で求めることが出来、伝送有効帯域の減衰歪はほぼ解
明されることになる。For transmission lines using long-distance cables or various coaxial cables, the frequency characteristics of the cable directly become attenuation distortion in the transmission band, degrading the line quality (it is necessary to insert a fixture to correct the frequency characteristics of the cable. is the song in Figure 1!I
As shown in 20, as the frequency increases, the loss increases. The loss is dominated by the capacitance and inductance of the cable, changes logarithmically with respect to frequency, and is directly proportional to distance and temperature. Therefore, the center frequency of the effective transmission band fz-
If the level difference (D2) between fs and f2 can be found, the level difference (Dl) between the center frequency and fx can be found as a ratio, and the attenuation distortion in the effective transmission band can be almost clarified. Become.

本発明は、上記の減衰歪特性を利用し、受信端で前記中
心周波数と上側周波数ｆ２のレベル差を測定し、それに
より受信端に挿入する減衰歪等什器の挿入数を制御しケ
ーブル伝送回線の減衰歪を自動的に等化する減衰歪の自
動等化方式の提供を目的とするものである。The present invention utilizes the above-mentioned attenuation distortion characteristics to measure the level difference between the center frequency and the upper frequency f2 at the receiving end, and thereby controls the number of attenuation distortion fixtures to be inserted at the receiving end. The object of the present invention is to provide an automatic attenuation distortion equalization method that automatically equalizes the attenuation distortion of the attenuation distortion.

次に、本発明の実施例を第２図に基づいて説明ｔｏ＝ｆ
七ｊ上となるが、ここではｆ２＝２ｆｏと仮！ 定する。ｆ・の周波数は周波数発振回路１により出力さ
れ、分配回路２＆Ｃ工や分岐されるが、その一方はＣｆ
Ｍを作る回路）波形変換回路３により矩形波とな９、さ
らに逓倍回路４によって２倍に逓倍され、ｆ！の周波数
となる。その出力は再び波形変換回路５に：より正弦波
となり結合回路６＆Ｃよって分配回路２の他方の出力（
ｆＯ）と結合されｆ・とｆｚ　の周波数が出力される。Next, an embodiment of the present invention will be explained based on FIG.
It is above 7j, but here we assume f2=2fo! Set. The frequency of f is output by the frequency oscillation circuit 1 and branched to the distribution circuit 2&C, one of which is output by the frequency oscillation circuit 1.
(Circuit for generating M) The waveform conversion circuit 3 converts the signal into a rectangular wave 9, which is then doubled by the multiplier circuit 4, and f! The frequency will be . The output is sent to the waveform conversion circuit 5 again: it becomes a sine wave and is sent to the other output of the distribution circuit 2 by the coupling circuit 6&C (
fO), and the frequencies f· and fz are output.

前記送信出力は出力端子ＯＵＴから、一般のケーブル伝
送回線７に伝送されｆｏとｆｚ　ｆｌケーブルの周波数
特性の影響を受けて受信端子ＩＮに入力される。その後
、切替器１７ｔ−通９分配回路８によって分岐される。The transmission output is transmitted from the output terminal OUT to a general cable transmission line 7, and is input to the reception terminal IN under the influence of the frequency characteristics of the fo and fz fl cables. Thereafter, the signal is branched by the switch 17t-9 distribution circuit 8.

その一方は、ｆｏを通過させる帯域Ｐ波器９によｐｍ出
され全波整流回路１０によって直流成分となる。又、一
方のｆ意ヲ通過させる帯域ＦｌｉＩｔ器１１１Ｃよって
抽出された信号は全波整流回路１２によって直流成分と
なり、前記のｆ・の直流成分とを比較回路１３によりて
比較され電圧長管検出する。その後、変換回路１４によ
ってディジタル量２進化に整えられて論理回路１５に送
られる。！理回路１５ではｆｚとｆｏとのレベル差に相
当する減衰歪等化回路１６のステップ数を判別し、接続
するか切り離すかの設定を行うもので設定後スイッチ１
７は切換える必要がある。One of them is outputted as pm by a band P-wave generator 9 that passes fo, and converted into a DC component by a full-wave rectifier circuit 10. Further, the signal extracted by the band FliIt device 111C that passes one f is turned into a DC component by the full-wave rectifier circuit 12, and is compared with the DC component of f by the comparison circuit 13 to detect the voltage. . Thereafter, the conversion circuit 14 converts the signal into a digital binary code and sends it to the logic circuit 15. ! The logic circuit 15 determines the number of steps in the attenuation distortion equalization circuit 16 corresponding to the level difference between fz and fo, and sets whether to connect or disconnect.
7 needs to be switched.

減衰歪等化回路１６は一般に第１図の曲線２１のような
減衰歪の逆特性を持っており、上記減衰歪に相当する減
衰歪等化回路を設定することにより第１図の曲線２０，
２１１−合成する事になり、減衰歪は等化されたことに
なる。The attenuation distortion equalization circuit 16 generally has an inverse characteristic of attenuation distortion as shown by the curve 21 in FIG. 1, and by setting the attenuation distortion equalization circuit corresponding to the above-described attenuation distortion, the curve 20,
211-composition, and the attenuation distortion is equalized.

本発明には以上説明したように、伝送有効帯域の中心周
波数と異った帯域内の周波数からレベル差を検出しその
情報によって減衰歪等化回路の段数を制御することによ
ってケーブル伝送回線の減衰歪全自動的に等化出来ると
−う効果がある。As explained above, the present invention is capable of attenuating a cable transmission line by detecting a level difference from a frequency in a band different from the center frequency of an effective transmission band and controlling the number of stages of an attenuation distortion equalization circuit based on that information. The effect is that distortion can be equalized completely automatically.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はケーブルの減衰歪と周波数との関係を示す特性
図、第２図は本発明の実施例を示すブロック図である。 １・・・・・・周波数発振回路、２．８・・・・・・分
岐回路、３・・・・・・波形変換回路、４・・・・・・
周波数逓倍回路、５・・・・・・波形変換回路、６・・
・・・・結合回路、７・・・・・・ケーブル伝送回線、
９，１１・・・・・・帯域Ｐ波回路、１０．１２・・・
・・・全波整流回路、１３・・・・・・比較回路、１４
・・・・・・変換回路、１５・・・・・・論理回路、１
６・・・・・・第　１　閃FIG. 1 is a characteristic diagram showing the relationship between cable attenuation strain and frequency, and FIG. 2 is a block diagram showing an embodiment of the present invention. 1... Frequency oscillation circuit, 2.8... Branch circuit, 3... Waveform conversion circuit, 4...
Frequency multiplier circuit, 5...Waveform conversion circuit, 6...
...Coupling circuit, 7...Cable transmission line,
9,11...Band P wave circuit, 10.12...
... Full-wave rectifier circuit, 13 ... Comparison circuit, 14
... Conversion circuit, 15 ... Logic circuit, 1
6...First Flash

Claims (1)

【特許請求の範囲】[Claims] ケーブル伝送回１ｌＩＯ伝送有効帯域のほぼ中心周液数
を持つａＥｌの信号と、前記中心周波数と異りた帯域内
の周波数を持つ第二の信号とを同時に伝送し、受信側で
前記第１および第２の信号から検出した到着レベルの差
に応じて回線に挿入すべき等什器の段数を制御すること
によりて、回線の減衰歪を自動的に等化するようにし几
こと′ｔＩＩ長とする減衰歪の自動等化方式。Cable transmission circuit 1l A signal of aEl having a frequency around the center of the IO transmission effective band and a second signal having a frequency within a band different from the center frequency are simultaneously transmitted, and the receiving side transmits the first and The attenuation distortion of the line is automatically equalized by controlling the number of stages of equalizers to be inserted into the line according to the difference in arrival level detected from the second signal. Automatic equalization method for attenuation distortion.
JP56123272A 1981-08-05 1981-08-05 Automatic equalization system for attenuation distortion Pending JPS5824246A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56123272A JPS5824246A (en) 1981-08-05 1981-08-05 Automatic equalization system for attenuation distortion

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56123272A JPS5824246A (en) 1981-08-05 1981-08-05 Automatic equalization system for attenuation distortion

Publications (1)

Publication Number Publication Date
JPS5824246A true JPS5824246A (en) 1983-02-14

Family

ID=14856451

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56123272A Pending JPS5824246A (en) 1981-08-05 1981-08-05 Automatic equalization system for attenuation distortion

Country Status (1)

Country Link
JP (1) JPS5824246A (en)

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